But the medications' benefits outweigh the downside, experts say
WEDNESDAY, Aug. 29 (HealthDay News) -- People taking rheumatoid arthritis drugs such as etanercept (Enbrel) or infliximab (Remicade) may be at a slightly increased risk for skin cancer, researchers report.
However, the risk is probably not significant enough to outweigh the benefits of these drugs, the researchers said.
These so-called biologic treatments work by blocking tumor necrosis factor alpha (TNF-alpha), which previous studies had found to be linked with increased risk of skin, lung and blood cancers.
"The risk of skin cancer is marginally increased among people with rheumatoid arthritis," said lead researcher Dr. Frederick Wolfe, a clinical professor of internal medicine at the University of Kansas School of Medicine. "But it's nothing that anybody should be worried about," he added.
For the study, Wolfe and his colleagues collected data on 13,001 patients with rheumatoid arthritis included in the National Data Bank for Rheumatic Diseases and the U.S. National Cancer Institute SEER (Surveillance, Epidemiology, and End-Results). The researchers found a total of 623 cases of skin cancer and 537 cases of other cancers.
They also found that anti-TNF-alpha medications were associated with a slight increased risk of skin cancer. But, they did not find any increased risk for other cancers, according to the report in the September issue of Arthritis & Rheumatism.
The heightened risk for skin cancer is very small, Wolfe emphasized. For melanoma, the most serious skin cancer, the increased risk is about two-fold; the actual risk is less than one in a thousand patients, he said.
"This is reassuring data," Wolfe said. "The fact that one didn't find an increased risk for other cancers looks like, in the short term, these drugs are safe," he said.
However, Wolfe noted that continued use of these drugs over the long term could reveal other problems.
One expert agreed that the benefits of TNF-alpha drugs far outweighed the risks to people with rheumatoid arthritis, an autoimmune disease characterized by chronic inflammation of the joints and tissue surrounding vital organs.
"The whole issue of the side effects of these biological agents is so controversial and unclarified," said Christopher Evans, the Robert W. Lovett professor of orthopedic surgery at the Center for Molecular Orthopaedics at Harvard Medical School.
"This study contradicts other studies that suggested greater risks. If the data hold up, I think it's encouraging for patients," he said.
Some patients with rheumatoid arthritis end up crippled, and their life expectancy is shortened, Evans said.
"If I were a severe rheumatoid arthritis patient whose quality of life depended upon these drugs, I'd continue to take them," he said. "The risk of melanoma is less than the risk of leading a shortened, miserable existence."
To learn more about rheumatoid arthritis, visit the Arthritis Foundation.
SOURCES: Frederick Wolfe, M.D., clinical professor of internal medicine, University of Kansas School of Medicine, Kansas City; Christopher Evans, D.Sc., Ph.D., Robert W. Lovett professor of orthopedic surgery, Center for Molecular Orthopaedics, Harvard Medical School, Boston; September 2007, Arthritis & Rheumatism
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